氯化原位接枝反应合成酐化CPE及结构表征

本硕士论文主要工作是利用氯化原位接枝反应对高密度聚乙烯（HDPE）进行氯化及醉基化。对上述反应体系的反应机理，产物的化学结构、链结构、反应条件对MAH接枝率（GD％）的影响以及物理机械性能等进行了详细的讨论。采用FT-IR和~1HNMR方法对氯化原位接枝反应的配化产物CPE-g-MAH进行了表征。二者均证明了MAH单体接枝到氯化聚乙烯主链上，证实了氯化原位接枝反应的可行性。并用~1HNMR，结合EI-Ms电喷雾质谱表征了氯化原位接枝共聚物CPE-g-MAH的链结构。反应过程中，主链及支链均被氯化。氯化原位接枝共聚物CPE-g-MAH凝胶含量的测定结果表明，在氯化原位接枝过程中没有交联反应的发生。论文中还研究了醉化CPE的合成过程。主要针对反应条件对MAH接枝率（GD％）的影响进行了详细的讨论，包括氯化原位接枝的温度模式、MAH单体量、氯气流量、氯含量等对MAH接枝率（GD％）的影响。同时探讨了氯化原位接枝反应历程。考查了氯化原位接枝MAH体系和氯化HDPE林系自由基浓度随时间变化的情况。接枝产物的硫化特性曲线表明：由于MAH的引入，聚合物主链上连接有酸配基团，使得氯化原位接枝共聚物CPE-g-MAH可以通过官能团之间相互反应而交联成为可能。随着MAH接枝量的升高，接枝率上升使得HDPE大分子链上带有更多MAH接枝点，CPE-g-MAH可硫化的程度相应提高。接枝产物的力学性能测试结果表明：随着MAH接枝率的增加，材料的拉伸强度上升，而材料的扯断伸长率、硬度等力学性能下降。

聚乙烯／淀粉共混物的光、生物降解性能研究

目前，可降解塑料作为一种解决塑料废弃物污染环境的最有效的全新技术途径，是各国塑料领域研究的热门课题之一。降解塑料大体可分为光降解、生物降解、光／生物降解和水降解塑料，其中光／生物双降解塑料的发展最快，形成产业化的商品也比较多。本论文选用通用塑料中应用最广泛的聚乙烯和天然可降解高分子材料中最具有代表性的淀粉作为共混体系，应用硬脂酸铁作为光敏化剂，系统的研究了共混体系的光降解特性和生物降解性能，同时还对淀粉的改性加工进行了研究。1、天然淀粉不具有热加工性能，采用甘油为淀粉的增塑剂，经过适当的工艺处理，可使其转化为具有加工性能的热塑性淀粉。并通过差热分析、流变学研究，讨论了热塑性淀粉的稳定性和加工性能。2、采用硬脂酸铁作为聚乙烯／淀粉共混物的光敏化剂，随着光敏化剂用量和光照时间的增加，聚乙烯和聚乙烯／淀粉共混物的力学性能呈明显下降趋势，分子量降低，碳基指数上升。说明硬脂酸铁对聚乙烯及其与淀粉的共混物具有很好的光敏化效果，在降解过程中伴有交联反应发生。同时，淀粉的加入对聚乙烯光氧化降解的发生具有促进作用。3、聚乙烯／淀粉共混物在堆肥一段时间后，表面出现大量的空洞，淀粉含量越高空洞越多，当淀粉含量）30％时，聚乙烯的分子量开始下降，说明共混物具有明显的生物降解特性。

无机刚性粒子增韧聚乙烯、聚丙烯的结构与性能研究

众所周知，聚乙烯、聚丙烯因其良好的加工性能及价格相对低廉而得到了广泛应用，但刚性和韧性的不足限制了它们在工程领域的应用。因此，提高聚乙烯、聚丙烯的刚性和韧性就成为高分子科学界和工程界一重要研究课题。本论文尝试用玻璃珠增韧聚云烯、聚丙烯，并系统研究体系的结构和性能，得到的主要结果有：1．成功实现了玻璃珠对高密度聚乙烯的增韧。在刚性、热稳定性显著提高的同时，玻璃珠增韧的高密度聚乙烯仍保持着很高的低温缺口冲击强度（-10℃，玻璃珠含量48wt％时，冲击强度为16KJ/m2）。2．得到了玻璃珠增韧高密度聚乙烯在脆韧转变点临界粒子间距（IDc）与温度的关系。这是第一条无机刚性粒子增韧热塑性聚合物体系的工Dc与温度的关系曲线。结果表明与弹性体增韧热塑性聚合物体系类似，工Dc随温度的升高而非线性增大。3．虽然没能在低温和常温下实现玻璃珠对聚丙烯的增韧，但是在较高的温度下仍发现了玻璃珠对聚丙烯有明显的增韧效果，且体系的脆韧转变温度随玻璃珠含量的增加而降低。4．用偏光显微镜（PLM）成功跟踪了所用聚丙烯p晶转变为仪晶的全过程。结果表明β晶能重结晶成以晶，重结晶生成的以晶熔点要比最初生成的a晶高五度左右。5．当聚丙烯存在两种晶型（a和β）时，实验发现聚丙烯／玻璃珠共混体系出现模量随玻璃珠含量增加先下降后上升的反常现象。进一步研究结果揭示该反常现象是玻璃珠填充和提高β晶形成能力二者竞争的结果6. 实验发现聚丙烯的β晶含量与添加玻璃珠的尺寸、含量及热处理温度有关。同样玻璃珠含量下粒子尺寸小有利于β晶的生成；对一定组成的共混物，存在一个最佳β晶形成温度。

聚甲基丙烯酸多缩乙二醇二酯－锂盐－溶剂三组份凝胶聚合物电解质的制备、导电性能和导电机理研究

由极性聚合物-碱金属盐构成的聚合物固体电解质（SPE）是一类很有前途的离子导电材料。但此类SPE，比通常非水介质电解质溶液约低3个数量级，故极需发展电导率更高的新型SPE材料。目前，由极性（或交联）聚合物、碱金属盐和高介电常数溶剂三组份构成的新一代SPE正在崛起，其室温电导率的达10~（－3）S·cm~(-1)。本工作以甲基丙烯酸多缩乙二醇二酯为大分子单体，研究了三组份凝胶电解质的制备、各组分的变化和温度等对膜强度和电导率的影响；并研究了该凝胶体系中离子传导机理。

糖原酸酯合成方法的研究以及二环糖胺的合成

在糖化学中，糖原酸酯是一类重要的合成中间体，广泛运用于1,2-反式糖苷的合成，尤其对于寡糖的立体选择性合成具有重要的价值。目前文献报道的制备糖原酸酯的方法大多存在对环境不友好的问题。本文对传统的糖原酸酯制备方法进行了改进，通过研究发现无机碱也能够有效地催化合成糖原酸酯。以溴代糖和醇（或糖基受体）为原料，在无机碱、四丁基溴化铵、乙腈的体系中，合成了一系列简单醇糖原酸酯和糖-糖原酸酯。 聚乙二醇及其衍生物作为有机反应的溶剂和催化剂在有机化学中有广泛的应用。本文阐述了一种以溴代糖和醇（或糖基受体）为原料，在无机碱和聚乙二醇二甲醚反应体系中合成糖原酸酯的方法。该方法中，聚乙二醇二甲醚即作为绿色溶剂又作为催化剂，反应条件温和、环保、高效。 糖胺是一类重要的糖苷酶抑制剂，已在糖尿病和其他代谢紊乱等疾病的治疗中发挥了极其重要的作用。本文提供了一种合成一类具有潜在的糖苷酶抑制活性、结构新颖的二环糖胺的途径。该合成思路是以1-叠氮基-2-C-乙酰甲基-3,4,6-三-O-苄基-2-脱氧-β-D-葡萄糖为原料，经二环糖亚胺中间体，通过二环糖亚胺还原或加成得到一类二环糖胺。 Sugar orthoesters as one of the most important intermediates in carbohydrate chemistry, are used extensively in the synthesis of sugar 1,2-trans-glycosides, especially oligosaccharide. These methods in the literature are mostly eco-unfriendly. Herein we described a modified protocol for the preparation of sugar orthoesters using inorganic base, by improving the conventional method. Our method involves the treatment of peracetylated or perbenzotlated glycosyl bromides with alcohols in the presence of a quaternary ammonium salt and an inorganic alkali in acetonitrile solvent, affording both simple sugar orthoesters and sugar-sugar orthoesters. Polyethylene glycol and their derivatives as solvents or catalysts play a significant role in the organic reaction. We developed a novel and environmentally benign methodology towards the synthesis of sugar orthoesters, which are prepared by the reaction of peracetylated or perbenzotlated glycosyl bromides and alcohols in the presence of dimethyl ether of polyethylene glycol as either the reaction medium or catalyst. Glycosylamines and pseudo-glycosylamines have been tested against various glycosidases, and applied to the treatment of diabetes and other metabolic disorders. We presented a route of the synthesis of a bicyclic glycosylamine as a potential glycosidases inhibitor with unique structure. Reduction of 2-C-acetlymethyl-β-glucopyranosyl azide derivative firstly produced a bicyclic glycosylimine intermediate, and subsequently the bicyclic glycosylamine and its derivatives would be prepared through the selective reduction or addition the C=N double bond of the bicyclic glycosylimine intermediate.

毛壳菌产抗真菌活性物质菌株筛选及种间原生质体融合研究

毛壳菌属很多种类具有重要生防价值，其生防机理包括对植物病原真菌的重寄生作用、诱导植物产生抗病性、产生抗真菌活性的次生代谢产物等。迄今，学界对毛壳菌的研究主要集中在毛壳菌的生防机理，毛壳菌活性次生代谢产物的分离等方面。本研究致力于产抗生素的毛壳菌的种间原生质体融合，从产抗生素毛壳菌菌株的筛选开始，进而对产抗生素的角毛壳菌进行诱变选育，最终用产不同抗生素的角毛壳菌与球毛壳菌进行种间原生质体融合。主要有以下五方面研究结果。 1、毛壳菌抗真菌活性物质产生菌株的筛选：不同毛壳菌菌株发酵液采用琼脂扩散法对植物病原真菌进行抑菌活性试验，结果显示，菌株CH08和CH23的发酵液对芒果炭疽、苹果炭疽和马铃薯晚疫菌具有抑制作用。菌株CH16和CH17的发酵液对芒果炭疽菌、苹果炭疽菌有抑制作用。菌株CH21发酵液对辣椒炭疽菌和西瓜枯萎菌有抑制作用。经形态学研究，菌株CH08、CH16、CH17和CH23鉴定为球毛壳菌，菌株CH21鉴定为角毛壳菌。对角毛壳菌与球毛壳菌菌株发酵液抑菌谱比较，发现角毛壳菌与球毛壳菌发酵液具有明显不同的抑菌谱，表明角毛壳菌与球毛壳菌产生不同的抗真菌活性物质。 2、角毛壳菌（CH21）和球毛壳菌（CH08）原生质体制备和再生条件研究：考察了菌龄、酶浓度、稳渗剂及其浓度、酶解温度、酶解时间及再生培养基对原生质体制备和再生的影响。用菌龄为生长54 h的角毛壳菌菌丝，以0.06 M磷酸缓冲液（pH6.0）配制成含蜗牛酶15 mg/ml、溶壁酶10 mg/ml、蔗糖0.6 mol/L的酶解液，30℃酶解1.5 h，原生质体释放量2.02×107个/g；以PDA为再生培养基，0.7 mol/L的蔗糖再生稳渗剂，再生率可达51.45%。用菌龄为生长48 h的球毛壳菌菌丝，以0.06 M磷酸缓冲液（pH6.0）配制成含蜗牛酶15 mg/ml、溶壁酶10 mg/ml、蔗糖0.6 mol/L的酶解液，30℃酶解1 h，原生质体释放量达1.57×108个/g；以PDA为再生培养基，0.7 mol/L的蔗糖为再生稳渗剂，再生率可达41.48%。 3、角毛壳菌（CH21）原生质体紫外诱变选育：以CH21为出发菌株，制备原生质体进行紫外诱变，诱变条件为：15 w紫外灯，距离30 cm，照射90 s，致死率80%~85%。建立了诱变菌株初筛的双层平板筛选模型。经平板初筛和摇瓶复筛，获得一株突变菌株CH21-I-402，其发酵液抑菌活性较出发菌株提高18.3%。 4、抗性标记菌株的获得：菌株CH21-I-402和CH08抗生素药敏试验表明， CH21-I-402菌株对潮霉素有抗性、对G418（Geneticin）敏感，菌株CH08对潮霉素和G418都敏感。根癌农杆菌EHA105介导的新霉素磷酸转移酶基因转化球毛壳菌，经PCR检测，新霉素磷酸转移酶基因成功转化进菌株CH08-GR70，CH08-GR120。转化子对G418抗性提高3～4倍，对潮霉素仍然比较敏感。 5、以G418和潮霉素抗性为筛选标记的原生质体融合与融合菌株AFLP分析：制备角毛壳菌CH21-I-402和球毛壳菌CH08-GR70原生质体，以35％的PEG6000为助融剂进行原生质体融合，以65 μg/ml的潮霉素和60 μg/ml G418为抗性筛选标记，获得46个再生菌株。再生菌株连续传代5代后，再生菌株表现出多种形态类型。利用AFLP技术对再生菌株及亲本菌株基因组DNA分析表明，再生菌株PF1、PF26为融合菌株。抑菌活性测试表明，融合菌株PF26发酵液对芒果炭疽菌和苹果轮纹菌有强的抑制作用，且抑菌活性比亲本球毛壳菌明显提高。 Chaetomium spp. have great potentials as biocontrol agents against a range of plant pathogens on the basis of its mycoparasitism, induced plant disease resistance, production of antifungal metabolites, and so on. Previous researches on C. spp. mostly focused on the mechanisms of its biocontrol and the isolation of secondary metabolites. In this study, screening antifungal C. spp., mutation breeding of C. cupreum and interspecies protoplast fusion between C. cupreum and C. globosum were carried out, respectively. The corresponding results are as follows: Firstly, among more than 40 C. spp., the strains produced anti-fungal antibiotics were screened by agar diffusion experiments. Results showed that both CH08 and CH23 had inhibition against Colletotrichum gloeosporioides, Cladosporium fulvum, and Phytophthora infestans. Both CH16 and CH17 had inhibition against Colletotrichum gloeosporioides and Cladosporium fulvum. In addition, CH21 exhibited anti-fungal activity against Fusarium oxysporum f. sp niveum and Colletotrichum capsici. Furthermore, CH08, CH16, CH17 and CH23 were identified as C. globosum, CH21 was proved to be C. cupreum based on morphology. The comparison of the anti-fungal spectrum between C. cupreum and C. globosum, showed they could produce different antibiotics. Secondly, specified protocols for preparing and regenerating protoplasts from mycelia of C. cupreum CH21 and C. globosum CH08 were studied. The effects of the age mycelia, the concentration of enzyme, digestion temperature and time, kinds of osmotic stabilizer and regeneration medium on protoplasts preparation and regeneration were all optimized, respectively. In one protocol, with 15 mg/mL snailase, 10 mg/mL lywallzyme, 0.6 M sucrose, in 0.06 M phosphate buffer (pH6.0), and digested for 1.5 h at 30 ºC, 2.02×107 protoplasts from each gram mycelia were obtained from cultures of C. cupreum CH21 grown in potato dextrose broth (PDB) medium for 54 h. And when 0.7 M sucrose was used as osmotic stabilizer in the regeneration medium OPDA (potato dextrose agar with osmotic stabilize), the regeneration efficiency of protoplasts was 51.45%. In another protocol, with 15 mg/mL snailase, 10 mg/mL lywallzyme, 0.6 M sucrose, in 0.06 M phosphate buffer (pH6.0), and digested for 1 h at 30 ºC, 1.57×108 protoplasts from each gram mycelia were obtained from cultures of C. globosum CH08 grown in PDB for 48 h. And when 0.7 M sucrose was used as osmotic stabilizer in the regeneration medium OPDA, the regeneration efficiency of protoplasts was 41.48%. Thirdly, the mutagenesis conditions and secondary screening model of C. cupreum CH21 were explored. An 80% to 85% death rate could be achieved when the protoplasts of C. cupreum CH21 were irradiated by 15 w UV lamp from 30 cm distance for 90 s. In addition, the doublelayer plate’s method for the primary screening of high-producing antibiotics strains was established. A high yielding antibiotic mutant CH21-I-402 was obtained through the primary screening on plate and the secondary selection in Erlenmeyer flask, compared to the original CH21 strain, the antifungal activity of the mutant CH21-I-402 was increased by 18.3%. Fourth, the sensitivity to antibiotics of both C. cupreum CH21-I-402 and C. globusm CH08 was detected. Results showed C. cupreum CH21-I-402 was sensitive to G418 (Geneticin) (Gs) and resistant to Hygromycin B(Hr), and C. globusm CH08 was sensitive to both G418 (Geneticin) (Gs) and Hygromycin B(Hs). At the same time, neomycin phosphotransferase II (npt II) gene was transformed into C. globusm CH08(Gs, Hs) mediated by Agrobacterium tumefaciens EHA105, and the npt II gene was verified by polymerase chain reaction in resistance to G418 strains CH08-GR70 and CH08-GR120. The transformants still showed sensitive to Hygromycin B(Hs). Finally, a selection system for hybrids was set up by interspecies protoplast fusion between C. cupreum and C. globusm using dominant selective drug resistance markers. At first, protoplasts of C. cupreum CH21-I-402 (Hr, Gs) and C. globusm CH08-GR70 (Hs, Gr) were prepared, then the protoplasts were fused in the presence of 35% polyethylene glycol 6000 and regenerated on OPDA medium with 65 μg/ml Hygromycin B and 60μg/ml G418, at last 46 colonies with Hr and Gr were obtained. Even after 5 generations’ subculture, most of the colonies displayed significant difference in taxonomic characteristics with their parental strains. Regenerated strains PF1 and PF26 were confirmed as fusants by amplified fragment length polymorphisms analysis with the genomic DNA as the model. PF26 showed higher inhibitory activity against Colletotrichum gloeosporioides and Macrophoma kuwatsukai than that of the parental strain C. globusm.

Micronuclei induction in human lymphocytes induced by carbon ions exposion along the penetrate depth of ions in water

Here we used cytokinesis-block micronucleus assay to measure the biological response along the penetrate depth of ions in water in human lymphocytes exposed to 100 MeV/u incident carbon ions in vitro. Polyethylene shielding was used to change the penetration depth of ions in water. A quantitative biological response curve was generated for micronuclei induction. The results showed a marked increase with the penetrate depth of ions in water in the micronuclei formation, which was consistent with a linearenergy- transfer dependent increase in biological effectiveness. The dose–response relationship for MN information was different at different penetrate depth of ions in water, at the 6 and 11.2 mm penetrate depth of ions in water, the dose–response relationships for the micronucleus frequencies induced by carbon ions irradiation were linear; while it was power function at 17.1 mm penetrate depth.

Monte Carlo studies of micromegas as a neutron detector and its track reconstruction

In this paper a two dimensional readout micromegas detector with a polyethylene foil as converter was simulated on GEANT4 toolkit and GARFIELD for fast neutron detection. A new track reconstruction method based on time coincidence technology was developed in the simulation to obtain the incident neutron position. The results showed that with this reconstruction method higher spatial resolution was achieved.

Neutron dose measurement in carbon ion radiation therapy at HIRFL (IMP)

For radiation protection purposes, the neutron dose in carbon ion radiation therapy at the HIRFL (Heavy Ion Research Facility in Lanzhou) was investigated. The neutron dose from primary C-12 ions with a specific energy of 100 MeV/u delivered from SSC was roughly measured with a standard Anderson-Broun rem-meter using a polyethylene target at various distances. The result shows that a maximum neutron dose contribution of 19 mSv in a typically surface tumor treatment was obtained, which is less than 1% of the planed heavy ion dose and is in reasonable agreement with other reports. Also the gamma-ray dose was measured in this experiment using a thermo luminescent detector.

Vulcanization of polybutadiene latex induced by Co-60 gamma radiation

Polybutadiene latex (PBL) vulcanization induced by Co-60 radiation and the influence of dose on crosslinking were investigated. Morphology and particle size distribution were examined by AFM and a particle size analyzer. The casting films were characterized for their swelling and mechanical properties as a function of dose.